diff --git a/modules/src/object/wr_ranlib.c b/modules/src/object/wr_ranlib.c
index 91274d71c..b515ffb3b 100644
--- a/modules/src/object/wr_ranlib.c
+++ b/modules/src/object/wr_ranlib.c
@@ -10,16 +10,27 @@ wr_ranlib(fd, ran, cnt1)
 	struct ranlib	*ran;
 	long	cnt1;
 {
-	{
-		register long cnt = cnt1;
-		register struct ranlib *r = ran;
-		register char *c = (char *) r;
+	struct ranlib *r;
+	long cnt, val;
+	char *c;
 
-		while (cnt--) {
-			put4(r->ran_off,c); c += 4;
-			put4(r->ran_pos,c); c += 4;
-			r++;
-		}
+	/*
+	 * We overwrite the structs in r with the bytes in c, so we
+	 * don't need to allocate another buffer.
+	 *
+	 * put4(r->ran_off, c) can fail if r->ran_off and c overlap in
+	 * memory, if this is a big-endian machine.  It tries to swap
+	 * the bytes from big to little endian, but overwrites some
+	 * bytes before reading them.  To prevent this, we must copy
+	 * each value before we overwrite it.
+	 */
+	r = ran;
+	c = (char *)r;
+	cnt = cnt1;
+	while (cnt--) {
+		val = r->ran_off; put4(val, c); c += 4;
+		val = r->ran_pos; put4(val, c); c += 4;
+		r++;
 	}
 	wr_bytes(fd, (char *) ran, cnt1 * SZ_RAN);
 }